Moms and dads who want to teach their children about money have some trendy tools at their disposal: kid-focused mobile banking apps, many of which come with personalized debit cards.

Youth banking apps are similar to their adult counterparts. Children and parents can access account information online, but children can also log in to their own subaccounts, generally with limited features. Many come with debit cards, and parents can fund by transferring money from an existing bank account. The mobile apps also let grown-ups monitor, and even limit, purchases — say, by setting a spending max of $20 at restaurants. Here's more on four buzzworthy apps:

Capital One MONEY. Many banking apps four young people don't pay returns, but this one lets children ages 8 and older set up an interest-earning checking account. It comes with a Mastercard debit card and allows kids to set aside money for savings goals. Parents can fund this account by linking it to either an existing Capital One adult account or an external bank account. There is no monthly service fee.

Chase First Banking. The Chase First Banking debit card account is available for ages 6 and older. As with many youth banking apps, parents can set limits on their children's spending. Kids can also set savings goals and track progress. The Visa debit card provides free access to 16,000 Chase ATMs. There is no monthly service fee, but a parent must be an existing Chase customer.

Greenlight. This app might not have a big bank's branding, but accounts are federally insured through a banking partner. Kids get their own Mastercard debit card, which parents can fund. Kids can set savings goals and parents can enable an optional roundup feature.

Purchases are rounded up to the nearest dollar, and the extra change is automatically sent to a savings pocket. Teens with jobs can also set up direct deposit into their Greenlight card. Accounts don't earn interest, but parents can choose to give "parent-paid" interest. Greenlight plans range from about $5 to $10 a month. There is no minimum age requirement.

FamZoo. This app can come with a prepaid debit card that lets parents monitor account activity and track balances. It also has an option to create a virtual "IOU" account. With this alternative, the parent or child manually enters transactions for funds held elsewhere — such as cash in a piggy bank. Or they can simply manage virtual IOU money in the app.

A FamZoo subscription is $5.99 a month, with discounts if parents prepay. Children under age 13 can receive a prepaid card in their parent's name.

E-mail: mburnette@nerdwallet.com. Twitter: @Margarette.